This image recently showed up on Reddit and gained a lot of attention (and comments). If you stare at the center of the picture of blurry colors below, the colors will slowly start to fade away and seem to disappear. If you break the stare, the colors will again reappear.

This visual phenomenon is very interesting, but it is nothing new. It was originally discovered by Swiss physician Ignaz Troxler way back in 1804. As such, it is commonly referred to as the Troxler effect or Troxler’s fading. It is nice to see that people are still fascinated by this visual effect more than two centuries after it was first documented.